140 TROPHON. 



last whorl with six squamose revolving lines ; lines of growth 

 membranaceous, crowded, undulated. Length 22, lat. 10*5 mill. 



Polar Sea. 



T. Mallzani. Kobelt (fig. 307), is an Alaska form in which the 

 varices are nearly entirely suppressed. 



T. MURTCATUS, Mont. PL 31, figs. 308, 311, 319. 



Yellowish or flesh-color, sometimes white (var. alba}. 

 Length, (; inch. 



England; Ireland ; Atlantic Coasts of France ; Spain ; 



Portugal; Mediterranean; 8-150 fathoms. 



The ova-capsules are described by Jeffreys MS about a line in 

 diameter, with an oval orifice ; they contain a purplish liquor^ 

 together with the fry. The animal is light yellow or whitish. 

 Eaten by fishes Trigla Gurnardi and Peristedion cataphractum. 

 It has also been taken, on a single occasion, from a fish caught 

 on the Massachusetts coast. 



T. BARVTCENSIS, Johnst. PL 31, fig. 318. 



Shell and animal white. The shell is broader, proportionally, 

 than T. mtiricatus ; it is also a little more shouldered, and has 

 fewer ribs, which are more laminar and prominent. 



Length, -fi--9 inch. 



North BritisJi ; Norway ; Mediterranean ; 8-200 fathoms. 



Creeps like Lachesis, foot upwards, on the surface of the 

 water. An ova-capsule was found by Mr. Jeffreys in a valve of 

 Leda minuta: it is very thin, semitransparent, and marked with 

 delicate, close-set, microscopic, concentric lines; orifice oval 

 The species bears the Roman name of Berwick-on-Tweed. 



So far the Mediterranean specimens have only been obtained 

 at considerable depths. 



T. CLATHRATUS, Linn. PL 31, figs. 312. 314, 316, 317, 322, 325. 

 Most authors separate this into two species, distinguished by 

 size and number of ribs. T. truncatus, Strom, (fig 325), is about 

 6 inch long, with twenty ribs on the body- whorl ; whilst T. 

 clalhratus, L. (fig. 312), has fourteen ribs when the same size, 

 and grows, moreover, to much greater dimensions. I have no 

 doubt that the British specimens are all small and correspond 



